This invention relates to the packaging of liquid or powder products, such as fruit juices, milk, sugar, salt, soap powders and the like and more particularly to a carton construction which provides both the required protective barrier sealing of the product while at the same time permitting ease of initial opening of the container for dispensing of the contents.
In the field of protective barrier packaging, it is essential that the interior surfaces of the container be completely covered or laminated with one or more barrier layer materials. This layer may be formed from metal foil for example, or alternatively, it may be defined by a laminate of several layers, with each layer being of a different composition, such as polyethylene, Surlyn, metallic foil, etc. Additionally, it is desirable that when the initial dispensing operation is to take place, thereby necessitating a breaking or a rupture of the barrier layer, that such rupturing takes place with a minimum of inconvenience to the consumer. Exemplary of the efforts of others to provide a pour spout construction which will result in the rupture of a dispensing opening seal upon initial use of the package are shown in U.S. Pat. No. 4,399,924 issued to Nilsson and U.S. Pat. No. 4,483,464 issued to Nomura. Other examples of combination liquid pour spouts and seals are illustrated in U.S. Pat. Nos. 4,469,249 and 4,600,127, both issued to Malpas et al.
Aside from the required barrier layer for packaging certain product types, such as potables, known methods and apparatus for fixing a pour spout to a paperboard container or blank, such as a gable top container or blank therefor, without an internal barrier layer, yield only relatively modest fixing rates.